Tie2 receptor tyrosine kinase, a major mediator of tumor necrosis factor α-induced angiogenesis in rheumatoid arthritis

Laura M. DeBusk, Ying Chen, Toshihide Nishishita, Jin Chen, James W. Thomas, Pengnain Charles Lin

Research output: Contribution to journalArticlepeer-review

91 Scopus citations


Objective. Rheumatoid arthritis (RA) is an inflammatory disease and an angiogenic disease. However, the molecular mechanisms promoting angiogenesis in RA are not clearly identified. Our objective was to study the role of an endothelium-specific receptor tyrosine kinase, Tie2, in angiogenesis of inflammatory arthritis. Methods. Expression of Tie2 and its ligand, angiopoietin 1 (Angl), in human synovium was examined by immunohistochemistry and Western blot. A novel synovium vascular window model was established to study the role of Tie2 in angiogenesis in vivo. Primary cultured endothelial cells and synoviocytes were used to study tumor necrosis factor α (TNFα)-induced Tie2 and Ang1 expression. Results. Tie2 was implicated in pathologic angiogenesis. We observed that Tie2 and Ang1 were elevated in human RA synovium. Using a novel collagen-induced arthritis synovial window model, we demonstrated that Tie2 signaling regulated arthritis angiogenesis in vivo. We also showed that Tie2 mediated TNFα-induced angiogenesis in a mouse cornea assay. In addition, we observed that TNFα can regulate Tie2 activation in multiple ways that may involve interactions between endothelial cells and synoviocytes. TNFα up-regulates Tie2 in endothelial cells through nuclear factor κB, and it up-regulates Ang1 in synoviocytes. These findings suggest paracrine regulation of angiogenesis between endothelial cells and synoviocytes. Conclusion. This study demonstrates that Tie2 regulates angiogenesis in inflammatory synovium. Tie2 signaling is an important angiogenic mediator that links the proinflammatory cytokine TNFα to pathologic angiogenesis.

Original languageEnglish
Pages (from-to)2461-2471
Number of pages11
JournalArthritis and rheumatism
Issue number9
StatePublished - Sep 1 2003


Dive into the research topics of 'Tie2 receptor tyrosine kinase, a major mediator of tumor necrosis factor α-induced angiogenesis in rheumatoid arthritis'. Together they form a unique fingerprint.

Cite this